This study is about party-system change in modern Greece and has two chief aims. First, it seeks to make sense of and explain the evolution of that country's party system from its early post-war years until today. Far from being ‘frozen', the Greek party system has displayed continuous transformations from a system featuring significant party fragmentation into another characterised by the high concentration of its political forces. Second, the paper proposes a classification of the changes that took place during the development of the Greek party system. This classification will yield three distinct types of party system which developed in consecutive order, namely, a predominant-party system (from 1952 to 1963), a system of polarised pluralism (between 1963 and 1981), and a two-party system (since 1981).